NEW YORK CITY—New maps created by a federal agency asserts that the East Coast in general—and New York in particular—is at high risk.
The East Coast may be able to produce larger, more dangerous earthquakes than previous assessments have indicated, according to Crain’s New York Business. That assessment comes courtesy of the newly released US Geological Survey. Representatives of the agency did not respond to a request for information.
On the plus side, the agency did say that earthquakes are a slightly lower hazard for New York City’s skyscrapers than previously thought. The 2014 maps were created with input from hundreds of experts from across the country. The bottom line for New York is that the area is at a slightly lower risk for the types of slow-shaking earthquakes that are especially damaging to tall spires but the city is still at high risk due to its population density and aging structures, says Mark Petersen, chief of the USGS National Seismic Hazard Mapping project.
“Many of the overall patterns are the same in this map as in previous maps,” says Petersen. “There are large uncertainties in seismic hazards in the eastern United States. New York City has a lot of exposure and some vulnerability, but people forget about earthquakes because you don’t see damage from ground shaking happening very often.”
It’s not the modern tall towers that are most at risk, Crain’s notes. But the city’s old eight- and 10-story masonry structures could suffer in a large quake, said Mr. Lerner-Lam. “If a structure is going to exist for 100 years, frankly, it’s more than likely it’s going to see an earthquake over that time,” says Arthur Lerner-Lam, deputy director of Columbia’s Lamont-Doherty Earth Observatory. “You have to design for that event.”
The new USGS maps will feed into the city’s building-code review process, asserts a spokesman for the New York City Department of Buildings. New York’s current provisions are based on the 2010 standards, but a new edition based on the just-released 2014 maps is due around 2016.
The new maps will help the insurance industry as a whole price earthquake insurance and manage catastrophic risk, says Nilesh Shome, senior director of Risk Management Solutions, the largest insurance modeler in the industry. The industry collects more than $2.5 billion in premiums for earthquake insurance each year and underwrites more than $10 trillion in building risk.
“People forget about history, that earthquakes have occurred in these regions in the past, and that they will occur in the future,” says Petersen. “They don’t occur very often, but the consequences and the costs can be high.”